export function autoSize () {
  let doc = document, win = window;
  let docEl = doc.documentElement,
    resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
    recalc = function () {
      let clientWidth = docEl.clientWidth;
      if (!clientWidth) return;
      // 这里的750 取决于设计稿的宽度
      if (clientWidth >= 750) {
        docEl.style.fontSize = '100px';
      } else {
        docEl.style.fontSize = 100 * (clientWidth / 750) + 'px';
      }
    };
  if (!doc.addEventListener) return;
  win.addEventListener(resizeEvt, recalc, false);
  doc.addEventListener('DOMContentLoaded', recalc, false);
}

// 字符串截取
export function trunc(value, length, separator) {
  let len = parseInt(length);
  let codes = separator ? separator.toString() : '...';

  return value.length < length ? value : value.substring(0, len) + codes;
}

// 手机或身份证号隐藏中间位数start前面保留的字符个数,end后面保留的字符个数
export function hideNum(str, start, end) {
  if (!str) return '';

  const length = str.length;
  const code = '*';

  let reStr =
    str.substr(0, start) +
    code.repeat(length - start - end) +
    str.substring(length - end);

  return reStr;
}
